Background: The aim of this study was to evaluate the long-term effects of continuous subcutaneous insulin infusion (CSII) therapy on the improvement of metabolic control and beta-cell function in patients with type 2 diabetes mellitus.

Methods: A single-center retrospective observational study was carried out in patients with T2DM who required CSII therapy due to suboptimal glycemic control. T2DM patients treated with the DANA-R Diabe care insulin pump (SOOIL Development Co., Ltd.) was followed for 6 years. Glucose control measures (hemoglobin A1c, total daily insulin dose) and beta-cell function (c-peptide index, insulinogenic index) were analyzed and clinical outcome data (body mass index, systolic/diastolic blood pressure, hemoglobin, serum protein, serum albumin, serum creatinine, total cholesterol, triglyceride, HDL, and LDL) were assessed after 2,4, and 6-years use of CSII. Statistical significances were calculated by Student’s paired t-test.

Results: Fifty-seven T2DM patients with mean age of 58.2±1.1 years were included in the study with 6 years (75.1±5.0 months) of follow-up. We found a statistically significant improvement in glycated hemoglobin (7.7±0.2, 6.3±0.1, 6.3±0.1, and 6.5±0.1%, p<0.0001), total daily insulin dose (48.6±3.1, 39.7±2.9, 34.2±2.0, and 34.4±2.2 U/day, p<0.0001), c-peptidogenic index (0.28±0.03. 0.42±0.07, 0.32±0.04, and 0.38±0.07, p<0.05), and insulinogenic index (3.28±0.53, 8.62±1.09, 6.47±0.74, and 5.84±0.96, p<0.001) after 2, 4, and 6-years use of CSII, respectively. Additionally, there were differences in clinical outcomes such as serum protein, albumin, total cholesterol, triacylglycerol, HDL, and LDL after 6 years.

Conclusions: The use of long-term CSII therapy for patients with T2DM led to a statistically significant and sustained improvement in glycemic control and beta-cell function.

Long-term follow-up, T2DM, Glycemic control, Beta-cell function, Insulin pump